1. Field of the Invention
This invention relates to a method for rapidly annealing amorphous metal by first immersing it in molten tin and then in a cooling fluid.
2. Description of the Prior Art
It has been known for over a decade that the soft magnetic properties of an amorphous metal alloy can be improved by magnetic annealing. See, e.g., B. S. Berry et al., Phys. Rev. Lett. 34, 1022 (1975) and F. E. Luborsky et al., IEEE Trans. Magn. MAG II, 1644 (1975). For transformer core applications, magnetic annealing--heating the core in the presence of an applied magnetic field--reduces the coercive force and induces uniaxial anisotropy, while reducing the stress introduced during the ribbon casting and core winding processes In the past, magnetic annealing was accomplished in ovens, and anneal times of several hours were required. Besides the time and energy costs involved in the conventional annealing process, an additional drawback is the fact that the alloy becomes brittle during annealing.
Annealing steel wire in molten lead is disclosed in The Making, Shaping and Treating of Steel, A.I.S.E., 10th ed., 1985, p. 998.